The 38-year-old of Rogers Meadow, Marlborough, is more than half way through his fundraising scheme ‘28 days of pain’, which sees him running around nine kilometres each day while on a strict diet.

ICP Support is a charity close to Mr Hill’s heart as his wife Rachel, 27, is 31 weeks pregnant with the couple’s third child and is suffering from a severe case of the liver condition intrahepatic cholestasis of pregnancy.

Mr Hill, editor of The Ocelot Magazine, said: “When I decided to take up the challenge Rachel wasn’t suffering with ICP.

“We have two other children and she was diagnosed eight weeks into those pregnancies so we thought this time she might come down with it, but she did 25 weeks in.

“Seeing her in pain reminds me why I’m doing this and hopefully one day a cure can be found, or an effective medication so that other people don’t have to suffer like we do.”

Mr Hill’s epic challenge will end in a 10-kilometre run at Longleat Safari Park on February 3.

He said: “I won’t be the fastest, I’ll probably be 10 minutes behind everyone, but I will complete it.

“There’s a part of the course called the hill, which I’m dreading because you have to do it twice and it’s really steep.”

Mr Hill has already raised £555 and in between his tough training he finds time to update his daily blog, so people can keep up to date with his progress.

Mr Hill said: “I tried to make it funny so it’s interesting to read.

“I’m overweight so it’s a tough challenge but I’ve already lost half a stone.”

The condition is connected with an increased risk of premature birth and Mr and Mrs Hill’s other children, George and Annabelle, were both born before 34 weeks. It can also cause foetal distress and stillbirth.

The support group was established more than 20 years ago by Jenny Chambers, who suffered stillbirth twice because of ICP.